1. Field of the Invention
The present invention relates to an arc welding apparatus, and more particularly to an arc welding robot and an arc welding robot system including an arc welding apparatus.
2. Description of the Related Art
A conventional arc welding apparatus 200, for example, as shown in FIGS. 12A and 12B, includes a multi-electrode type welding torch 202, a first wire feeder 204a and second wire feeder 204b, and a first torch cable 206a and second torch cable 206b, all of which are mounted on a robot mechanical part 208. The welding torch 202 is fixed to a wrist element 210 of the robot mechanical part 208. The first wire feeder 204a and second wire feeder 204b are connected to the welding torch 202 by the first torch cable 206a and second torch cable 206b to feed a plurality of types (in the illustrated example, two types) of welding wire to the welding torch 202. The first wire feeder 204a and second wire feeder 204b selectively feed the welding wire to the welding torch 202 in accordance with an instruction from a not shown welding controller.
In another arc welding robot, a plurality of sets of welding torches, torch cables, and wire feeders are provided and the welding torches of the sets are adapted to be exchangeably attached to the robot mechanical part by a not shown tool changing means. In this arc welding robot, for example, the welding torch of the set used is fixed to the wrist element of the robot, while the welding torches of the other not used sets are fixed to holding means as connected with the torch cables and wire feeders of their sets. These welding torches can be changed in accordance with need and used for welding.
In a conventional arc welding robot, since a multi-electrode welding torch was fixed to the front end of the robot and the plurality of torch cables and the plurality of wire feeders associated with these torch cables were necessary, there were the problems that the wire feed section was large and could be easily interfered with other peripheral equipment or structures and also the wire feed section was heavy and the load on the robot mechanical part was great.